Vegetables can be grown in a variety of containers, as long as the containers have sufficient drip holes. You can use plastic trashcans of any size for container gardening. Simply drill or cut at several 1-inch holes in the bottom of the trash cans for drip holes. Choose appropriate-sized containers for each type of vegetable.
Potatoes grow well in containers. The container should be at least 2 feet wide and 2 feet deep for each plant. Regular potting soil is sufficient to grow potatoes. Several brands of potting soil have fertilizer mixed in, so you do not have to add fertilizer. If you make your own potting soil (one part each of builder's sand, loam and peat moss), add slow release fertilizer (14-14-14). Cut a potato into pieces, making sure there are at least two eyes in each section. Fill the container three fourths of the way with potting soil. Lay the potatoes on the top of the soil, then add 3 inches of potting soil on top of the potato. Water well, making sure all the soil is moist.
Plant five or six radish seeds in a container that is 18 inches wide by 2 feet deep. Various cultivars might require different depths for planting the seeds, but if the seeds lack instructions, plant the seeds about 1 inch deep into the potting soil. Gently water, so as not to wash away the soil over the seeds, but water deeply. If your hose has a mist function, mist the seeds for about 10 minutes. Once the seeds sprout, you can use a lighter sprinkle. Make sure to moisten at least 2 inches of the soil. Once the radishes start growing and the seedlings become stronger, water until the water comes out of the drip holes.
Peppers (sweet or hot) grow well in containers. The container should be at least 2 feet deep and 18 inches wide for each plant. Plant the seeds according to the instructions on the pepper plant. Water with a mister until the seedlings emerge, then water with a sprinkler. During the first few weeks, make sure you water enough so that the top 3 inches of soil are moist. Once the seedlings emerge, water until water seeps out of the drip holes. Watering deeply encourages more root growth, which makes the plant healthier and able to produce more fruit.